Removable contact-finger tip.



No. 755,743. PATENTED MAR. 29, 1904.

' F. E. CASE.

" REMOVABLE CONTACT FINGER TIP.

APPLICATION FILED JULY 9, 1902.

NO MODEL.

[river-H101":

UNITED STATES Patented March 29, 1904.

PATENT 1 OFFICE.

FRANK E. CASE, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

REMOVABLE CONTACT-FINGER TIP.

SPECIFICATION forming part of Letters Patent No. 755,743, dated March29, 1904.

Application filed July 9, 1902. Serial No. 114,873. (No model.)

To all whom it may concern/.-

Be it known that I, FRANK E. CASE, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Removable Contact FingerTips, of which-the following is a specification.

This invention relates to contact-fingers for electric controllers, andhas for its object the provision of removable tips therefor which may besecured immovably to the fingers and will have a large area of contacttherewith,

- but which may beeasily and cheaply replaced.

.tact portion is no longer fit for service.

The only part of the finger which is subject to deterioration is thecontacting portion, which, because of the wear due to friction of theparts and theburning of the metal by the electric arcs at that point,may deteriorate rapidly. As usually constructed the finger is made inone piece, which necessitates that the whole finger be thrown away whenthe cony the use of my removable tip, which can be cheaply manufacturedand applied, the main portion of the finger may be retained.

I have illustrated my invention as applied to a form of finger which isfrequently employed in controller construction.

Referring to the attached drawings, Figure 1 is a view in elevation,showing a finger as usually mounted in a controller supplied with myremovable tip. Fig. 2 is a perspective view of an unmounted finger alsoprovided with my removable tip, and Fig. 3 is a perspective view of theremovable tip itself.

Referring to the drawings in detail, A is an insulated support uponwhich is mounted a brass casting B. Spring-mounted upon brass castings Bby means of spring S is contact-finger F, having in one side awedge-shaped recess D, in which is secured the removable tip T by meansof its rivet portion 7, said rivet portion being formed integral withsaid tip. The tip T has a curved contact-surface s, and upon theopposite side is a wedge-shaped projection formedby the walls orsurfaces a and b, which is adapted to enter and fit closely into therecess D. This construction gives a large contacts at the surface S andbetween the tip and finger may be seriously impaired.

K is a movable contact-surface against which the contact-tip T ispressed by the action of spring S, and when not in contact with thatsurface it is maintained in position by the rigidity of spring S. Itwill also be noted that when the contact-tip is in engagement with themoving surface K the strain on the said tip is taken up by one side wallof the recess D and is almost entirely removed from the rivet, since thewedge-shaped recess is formed across the finger F in a direction atright angles to the direction of movement of said contact-surface K.

The tip T may be drop-forged and the finger F manufactured in the mannerusually followed in producing fingers of this character. The cost of thefinger when constructed in accordance with my-present invention willtherefore exceed that of the usual integrally-formed finger and tip by atrivial amount; but this will be more than offset by the decreased laborin renewing the fingers.

When desired, the tip may be removed by simply removing the headof therivet with a cold-chisel. A new tip may then be riveted in position.

Other forms of finger-tips may evidently be employed without departingfrom my inven tion, and I do not, therefore, wish to be limited to thespecific construction shown inthe drawings. 7

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. The combination with a contact-finger recessed at one end and havinga hole extending therethrough, of a removable contact-tip having aprojection engaging said recess, and a rivet portion extending throughsaid hole so as to fasten said tip rigidly to said finger.

2. The combination with a contact-finger tip having a contact-face and awedge-shaped projcction opposite said contact-face, of a contactfingerhaving a hole therethrough and a wedgeshaped recess extending acrosssaid finger at right angles to the axis of said hole, and means forsecuring the tip to the finger, the said means being adapted tocooperate with said projection insuch manner as to prevent relativemovement of said tip and finger and to allow the strain on said tip whenthe latter is in engagement with a moving contact-surface to be taken upby one of the side Walls of said recess.

3'. The combination with a contact-finger tip having a contact-face anda wedge-shaped projection opposite said contact-face and also a rivetportion extending from said projection, of a contact-finger having aWedge-shaped recess extending across said finger in a direction at rightangles to the direction of movement of the contact-surface with whichthe contactface of said tip is adapted to engage and also having a holeextending therethrough for receiving said rivet portion.

4. As an article of manufacture, a contactfinger tip having a curvedcontact face, a wedge-shaped projection opposite said face, and a rivetportion formed integral with said tip and extending at right angles fromsaid projection.

5. As an article of manufacture, a contactfinger having upon one side awedge-shaped recess extending across said finger adapted to receive aremovable tip, and a hole extending from said recess to the oppositeside of said finger and at right angles to said recess.

In witness whereof I have hereunto set my hand this 3d day of July,1902.

FRANK E. CASE.

Witnesses: v

BENJAMIN B. HULL, HELEN ORFORD.

